Patents by Inventor Yoshiaki Kumakura

Yoshiaki Kumakura has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Ad conversion circuit, semiconductor device, and ad conversion method
    Patent number: 8816888
    Abstract: A reference voltage generator generates a reference voltage at the time of sampling a received input signal. A sampling time controller detects a change in the reference voltage. When the reference voltage rises to a determined threshold, the sampling time controller determines that sampling is completed, and generates a sampling clock in which sampling time is controlled on the basis of an external clock.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: August 26, 2014
    Assignee: Fujitsu Semiconductor Limited
    Inventor: Yoshiaki Kumakura
  • AD CONVERSION CIRCUIT, SEMICONDUCTOR DEVICE, AND AD CONVERSION METHOD
    Publication number: 20140097978
    Abstract: A reference voltage generator generates a reference voltage at the time of sampling a received input signal. A sampling time controller detects a change in the reference voltage. When the reference voltage rises to a determined threshold, the sampling time controller determines that sampling is completed, and generates a sampling clock in which sampling time is controlled on the basis of an external clock.
    Type: Application
    Filed: September 26, 2013
    Publication date: April 10, 2014
    Applicant: FUJITSU SEMICONDUCTOR LIMITED
    Inventor: Yoshiaki KUMAKURA
  • Switched capacitor circuit and pipelined analog-to-digital conversion circuit with the switched capacitor circuit
    Patent number: 8159383
    Abstract: A conversion circuit for converting a differential input signal into an output signal includes an amplifier that has an input terminal and an output terminal; a first capacitor in which, in a first period, a difference voltage of the differential input signal is applied across first and second terminals, and in a second period the first terminal is coupled to the output terminal of the amplifier and the second terminal is coupled to the input terminal of the amplifier; and a second capacitor in which, in the second period, a reference voltage in accordance with the differential input signal is applied to a first terminal, and the second terminal of the first capacitor is coupled to a second terminal of the second capacitor.
    Type: Grant
    Filed: June 7, 2010
    Date of Patent: April 17, 2012
    Assignee: Fujitsu Semiconductor Limited
    Inventor: Yoshiaki Kumakura
  • SWITCHED CAPACITOR CIRCUIT AND PIPELINED ANALOG-TO-DIGITAL CONVERSION CIRCUIT WITH THE SWITCHED CAPACITOR CIRCUIT
    Publication number: 20100308870
    Abstract: A conversion circuit for converting a differential input signal into an output signal includes an amplifier that has an input terminal and an output terminal; a first capacitor in which, in a first period, a difference voltage of the differential input signal is applied across first and second terminals, and in a second period the first terminal is coupled to the output terminal of the amplifier and the second terminal is coupled to the input terminal of the amplifier; and a second capacitor in which, in the second period, a reference voltage in accordance with the differential input signal is applied to a first terminal, and the second terminal of the first capacitor is coupled to a second terminal of the second capacitor.
    Type: Application
    Filed: June 7, 2010
    Publication date: December 9, 2010
    Applicant: Fujitsu Semiconductor Limited
    Inventor: Yoshiaki KUMAKURA